Adsorption of NO on ZnO monolayer doped with transition metal (Ti, V, Cr, Mn, Co, and Zr): The first-principles study

Nitric oxide (NO) is a harmful gas produced by fuel combustion in the petrochemical industry. In this paper, the gas sensitivity of NO molecule on ZnO monolayer (ZnO-ML) doped with transition metal (TM = Ti, V, Cr, Mn, Co, and Zr) is systematically investigated by the first-principles calculation. The results show that the adsorption mode of NO molecule on the doped system (TM-ZnO-ML) changes from physisorption to chemisorption, and adsorption energies range from-1.59 eV to-3.12 eV, which are 8-16 times the origin adsorption energy (-0.19 eV) on the pristine ZnO-ML. Meanwhile, the charge transfer between NO molecule and substrates increases by 4-13 times compared with the pristine ZnO-ML. Furthermore, under the applied electric field of-0.4 V/& Aring;, the charges transferred from V-ZnO-ML to the NO increase to 0.54 e . All of the results reveal the broad application prospect of TM-ZnO-ML in NO gas sensors.